Battle of Blue fuel with Blue energy - myth or reality?

Sit at the keyboard this time I was forced by a recent article in Vedomosti about the mysterious blue energy that threatens the power of Gazprom in Europe. The bold predictions of the female authoring team amazed with their prospects. According to their calculations, it turned out that by utilizing the three largest rivers in the EU for the production of “blue energy” - the Danube, the Rhine and the Vistula - only 10% of the potential can produce electricity 3 times more than all EU countries managed to consume in 2012. It is promised that after several years of technology improvements, the cost of received energy should drop to 8 eurocents. For comparison, today the cost of 1 kWh of wind power in Europe is 10-20 euro cents, and of coal 6-10 euro cents, depending on the generation technology.

The conclusion made by journalists is very bold. In just a few years of development, new technologies are able to significantly press off the use of gas as a source for generating electricity and allow the European Union to reduce gas demand by 35-40%. This means that in case of success of the “blue energy” Russian blue fuel will cease to be relevant for Europe.
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I turned out to be less optimistic than girls, and decided to dig deeper to understand whether Gazprom and the developers of shale gas are worth fearing a new competitor. I invite those wishing to get acquainted with my micro-research under cat.

A brief history excursion

As many have probably guessed from the context of the introduction, we are talking about the energy obtained on the basis of the osmotic effect. The phenomenon of osmosis has long been known. It was first observed by A. Podlo in 1748, but a detailed study began a century later. In 1877, the German botanist Wilhelm Pfeffer measured the osmotic pressure for the first time while studying aqueous solutions of cane sugar.


Wilhelm Pfeffer

In 1887, on the basis of data from Pfeffer's experiments, Vant-Hoff established a law that determines the osmotic pressure depending on the concentration of the dissolved substance and temperature. He showed that the osmotic pressure of the solution is numerically equal to the pressure that the solute molecules would have had if they were in a gaseous state at the same temperature and concentration values.

Technology

So, where rivers flow into the seas and oceans, we have huge sources of both fresh and salt water in the neighborhood - this is the perfect place to build osmotic power plants. How to get energy? The easiest way is to place water in a tank that is divided into two compartments with a semi-permeable membrane.



Sea water is supplied to one compartment and fresh water to another. Due to the different salt concentrations in the sea and fresh water, water molecules from the freshwater compartment, trying to equalize the salt concentration, pass through the membrane into the marine compartment. As a result of this process, an overpressure is formed in the compartment with sea water, which in turn is used to rotate the hydro turbine generating electricity.

There are alternative ways. One of them was suggested by Italian Doriano Brogioli. The basis of its technology is an electric double layer capacitor. “The basic idea is that the potential of an electrical double layer depends on the concentration of ions,” says the inventor.

He proposed to build such a capacitor from two plates created from highly porous carbon. First, it is supplied with sea water, in which, as is known, an unlimited amount of chlorine and sodium ions is always present. To start the system into operation, the plates should be energized from the “starter” power source. Then the positive electrode will attract chlorine ions, and the negative one will attract sodium ions.

Further, fresh water is supplied to the device. The difference in salt concentration causes the ions to leave the plates and go away, overcoming the action of electrostatic forces. The voltage on the electrodes with this grows noticeably. In the future, the system itself produces current, while saline and fresh water enters the apparatus. A similar solution was proposed by the physicist Roberto De Luca (Roberto De Luca), also Italian, only his field created a permanent magnet.

Reality

However, only the first method went beyond the laboratory research facilities. 11/24/2009 The first power station in the world based on the osmotic effect started its work in Norway.

It was built by Statkraft in the town of Tofte, on the territory of the Södra Cell Tofte pulp and paper mill. The construction of the power plant cost $ 20 million and required ten years of research and technology development.



1: Exterior of the power station at Tofte, south of Oslo. 2: Pre-filtration of water to avoid membrane blockage. 3: The membranes are convoluted in pressurized vessels to create high pressure. 4: Turbine used to generate electricity.

Immediately after the launch, this power plant produced no more than four kilowatts of electric power, but in the course of improving the technology, the creators planned to increase this value to as much as 10 kilowatts. Did they succeed in this for the time being a mystery covered in darkness, and whether plans to build a power plant for a village of 10,000 private houses will be embodied this year.

Until recently, the power station in Norway was the only one in the world, but according to Vedomosti, the Netherlands joined the race. On November 26, 2014, a small plant of REDstack BV was launched in Afsluitdeike. The power of their experimental power plant according to some data can already be 50 kW. It was funded by the Dutch government.

Sleep well, our wealth! The battle is postponed.

So, theoretically, due to the osmotic effect, it is possible to obtain a pressure equivalent to 120 meter water column and using a flow of one cubic meter per second to generate energy of 1 MW. Almost today, this parameter is 2-3 watts. Scientists' immediate goal is to reach a level of 5 W, which they say can bring technology closer to self-sufficiency.

It seems that while Gazprom can calmly calm down, concentrating its activities on the problems arising from the cheapening of shale gas production and see how the plant launched in the Netherlands goes to full capacity, sufficient to meet the needs of 800,000 inhabitants, only in nightmares.

There are too many unsolved problems with the “blue energy of water”. The main sticking point in the membranes. It is necessary to improve their efficiency in a revolutionary way, at the same time reducing the cost. Making the membranes withstand tremendous pressure will also not be easy. Finally, we must not forget that the water must be very well cleaned before being fed into the power unit, otherwise the lifetime of the membranes will be too short. Creating cheap and effective filters is also not very easy. Eh, where is Chubais with his Rosnano!

An important addition. The intrigue remains!

Thanks to the meticulousness (in a good sense of the word) of the user under the nickname AYrm, I was able to find information about what is meant by “Blue Energy” (BlueTech®). There are not too many details, but this is better than nothing. It turned out that the power plant built by REDstack and Fujifilm near Afsluitdijk in the Netherlands is based on Reverse Electro Dialysis (RED) technology. Specially I keep the original names to ease the task of those who decide to try their luck in finding the details. Fujifilm's main contribution seems to be the development of a key component - membranes.
However, the additional information that has been found so far is extremely mean. It is clear that the bath technology does not apply water turbines. It seems that it uses the principle proposed by the Italian I mentioned above, Doriano Brogioli or very similar to it. The object itself seems to be built.

The project’s home site states that the launch of the pilot power unit was to be held on February 14, 2014, and its capacity would be 50 kW. Information about whether this event occurred on time and turned out to be successful, I could not find. Thus, the intrigue is preserved. Whether the project is classified for the time being from the excessive attention of energy monsters exploiting fossil fuels, or something went wrong. Time will tell whether Gazprom can relax.
In conclusion, I provide a link to the website of the company REDstack, promoting this technology. There is also a promotional video on which, however, you can watch only the laboratory installation.
http://www.redstack.nl/
The most detailed way to obtain osmotic energy without the use of turbines proposed by Doriano Brodgioli in Russian is described here:
http://elementy.ru/news/431152?page_design=print

Well, now my conscience is clear!